The credit unions in my area only work with bigger companies so just know I have already reached out. 

I'm not sure what the current appraisal value is, but comps in the area range from $600k to $1M+.

How to Invest in Real Estate and The Book on Real Estate Investing are a couple great books published by bigger pockets. congrats on taking the first step.

I agree with what Rick stated but believe he intended this for a single ADU in a single family zoned area.  

For example, should we focus on acquiring one high-quality property in a strong market, or would it make more sense to spread the investment across multiple lower-cost units in emerging areas?

I have closed projects in Pittsburgh before, so the area I am comfortable with.

Have you checked to see what others are doing in the immediate area on VRBO and AirBNB?

Also look outside the area .

Mobile apps are a bit harder to maintain than the site, and browser features keep closing the gap.

Quote from @Ashley Kehr: There are a ton out there, but if you are starting out to mid level I like buildium.